1. Field of the Invention
The present invention generally relates to a pagoda-shaped umbrella having a contractible topmost extension of a center post to shape a canopy of the umbrella as a pagoda, and in particular to a pagoda-shaped umbrella having bars axially extendible from the top end of the center post to form a tee of the pagoda with a simple mechanism.
2. The Related Art
A conventional pagoda-shaped umbrella, as illustrated in FIG. 5 of the attached drawings, comprises an upright center post 30 having a lower supported on a base (not labeled) and an upper end to which a crown 32 is attached, a runner 31 movable along the center post 30, a plurality of ribs 33 pivoted to and radially extending from the crown 32 and stretchers 34 coupled between the ribs 33 and the runners 31 whereby when the runner 31 is moved toward the crown 32, the ribs 33 are driven upward by the stretchers 34 to open a canopy 35 mounted to the ribs 33. An axle 38 coaxially and telescopically extends from the upper end of the center post 30 and forms a top canopy retainer 36 at an upper end thereof. A helical spring 37 encompasses the axle 38 and is retained between the canopy retainer 36 and the crown 32 to bias the retainer 36 upward and away from the crown 32 to form a tee of a pagoda. When the umbrella is opened by moving the runner 31 toward the crown 32, the particularly configured canopy 35, under the action of the spring force of the spring 37, allows the axle 38 to move upward and thus making the retainer 36 away from the crown 32 to support the canopy 35 as a tee of a pagoda.
The conventional device that makes use of the spring force to support the retainer 36 at a distant position suffers fatigue of the spring 37, which reduces the spring force to expand the canopy to form the pagoda shape. Thus, the overall configuration of the canopy, after being expanded by the reduced spring force, is no longer maintained as a pagoda. The service life of the umbrella is thus shortened. In addition, the axle 38 is a must for properly supporting the spring 37 in position. The axle 38 must extend through the crown 32 in a telescopic and coaxial manner. This complicates the manufacturing process and the increases costs.
Thus, the present invention is aimed to solve the problems of the conventional pagoda-shaped umbrellas.